Most of the downloaded files are icons, please see that asset page to learn what icon name represents what exactly (
Night Elf Huntress - you can get there also using a button above, below the model description). The base icon is the one named ...
BTN.
The custom Decorations.blp texture needs to be imported
only once and a custom path must be set for it, removing "war3Imported/" from inside of it.
The rest should be easy. Set the model file for a unit into the object editor, do the same with the custom missile if you want.
I'm attaching a testmap to show how to make these models work